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Gain Tuned Internal Model Control for Handling Saturation in Actuators. 學生 : 吳政達 授課老師：曾慶耀 教授. 2007/11/15. Abstract. In this paper, a new approach to handling actuator saturation based on Internal Model Control (IMC) is proposed.
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Gain Tuned Internal Model Control for Handling Saturation in Actuators 學生: 吳政達 授課老師：曾慶耀 教授 2007/11/15
Abstract In this paper, a new approach to handling actuator saturation based on Internal Model Control (IMC) is proposed. a gain term and first-order exponential filter are tuned to desaturate the actuator. Examples show the simplicity of design and the validity of proposed framework.
Introduction The existence of control signal saturation within a practical control system may result in instability. The research in control signal saturation has reached the level of maturity where ad-hoc compensation schemes are widely available.
Introduction Internal Model Control (IMC) is a control technique that guarantees system stability while offering good tracking performance.
Introduction The only restrictions on the IMC scheme are that the plant needs to be open loop stable and minimum phase. The proposed method not only reduces the complexity of currently available saturation compensation schemes, but also guarantees global stability for bounded input bounded output (BIBO) systems.
Restructured IMC A. Single-degree-of-freedom IMC with Saturation
Restructured IMC The following equation relating the inputs and outputs can be derived
Restructured IMC B.Two-degrees-of-freedom IMC A typical discrete-time teo-degrees-of-freedom IMC structure is shown in Fig. 2.
Restructured IMC C.Proposed IMC Framework The proposed IMC structure with control input saturation is thus constructed in accordance with this proposition with the saturated input fed into the plant and model.
Inverse Model Controller First order exponential filter Restructured IMC C.Proposed IMC Framework
Restructured IMC The saturation function is given by： A single static saturation non-linearity function defined by (6) can be characterized by：
Stability Analysis The closed-loop system remains globally stable as long as the plant model is equal to the nominal model (Gp=Gm).
Stability Analysis The following equations can be derived from Fig. 3：
Stability Analysis Consider a single-input-single-output nonlinear system represented by the feedback connection as shown in Fig. 5
Conclusion Overshoot can be eliminated by increasing gain, K. The stability analysis in section III showed that the proposed IMC structure is globally asymptotic stable. The modified IMC synthesis can be used for the handling of other sector-bounded non-linearities.
